Can't say I had a definite favourite. Sure, I loved all the classics (Tom & Jerry, Road Runner, Bugs/Daffy etc etc), but I typically fell in with some of the slightly more obscure/niche cartoons - Danger Mouse, Bucky'O'Hare, the Sonic Adventures every Sunday on Channel 4 (ps. nice to see the Robotnik of that era became a hot trending meme/youtube poop in the not-so-distant past - Long John Baldry did stellar voice-work for Robotnik, and ironically voiced Komplex in Bucky as well which I only figured out recently).
I was more of a Knightmare or "Games Master" viewer, really. Apparently loved Thomas the Tank Engine when I was super-duper young - none of which were cartoons. I don't even watch much TV in the present so I can't even give a recent name
I guess I'll just say Dr.Robotnik for the sake of giving an answer... I mean, when he can insult people by calling them 'BOOBS
', 'FISH FONDLING FRUITCAKES
', or say the word 'blasted' so much that you can mishear it as 'bastard' quite frequently, how can you not like this supposed 'children's TV' character? Or maybe I'm biased because various 'proper' YouTube Poops involving Robotnik can still make my ribs sore from laughing here in 2018.